Well, you certainly can, but don't expect restore to work on
compressed files! e2dump hasn't yet been modified to save the
information that certain clusters are compressed. Thus, when restoring
compressed files, it will not restore the cluster's bits that say if
there are compressed or not. Data won't really be lost, but you will
have a direct access to raw compressed data, and transparent
decompression will not occur. This is almost certainly not what you
want. [However, e2decompress can be coerced into decompressing
the file -- pjm.]

I'm sorry but you'll have to use something else to make your backups, or
wait until someone else modifies e2dump, or do it
yourself....